A generic method for wet-finishing textile goods is known from German patent 958 914. In the performance of this method, the textile goods are placed in a vessel closable in a pressure-tight manner on a material holder, the interior of which is connected to a line which leads to the intake side of a circulating pump or a compressor. The compression side of the circulating pump is hydraulically connected via a further line to the vessel interior. Arranged parallel to this gas circulating pump serving to convey air through the textile goods located in the vessel is a liquid pump, the intake side of which is connected to a water trap connected upstream of the gas circulating pump. The compression side of the liquid pump is connected to injection nozzles arranged in the line on the compression side of the gas circulating pump.
The vessel is furthermore connectable to a vacuum source and allows the treatment liquor to be introduced via a further line.
The wet-finishing is carried out by all of the aerating valves of the vessel first being closed and the vessel then being connected to the vacuum source by an appropriate valve being opened. A line for the treatment liquor is simultaneously opened so that the developing negative pressure will aspirate the treatment liquor into the vessel and consequently into the textile goods. The treatment liquor flows in on a side of the textile goods that in the further course of the treatment process will be connected to the intake side of the gas circulating pump.
When the textile goods in the container have been flushed in this way with the liquor, the vacuum source is switched off and instead the vessel is aerated towards the atmosphere. The resulting pressure surge serves to uniformly distribute the liquor in the textile goods.
This procedure is repeated several times, and the gas circulating pump is then put into operation after the liquor has been let off. The gas circulating pump forces the air located in the system through the textile goods and hence carries the liquor along with it out of the textile goods. The entrained liquor carried out of the textile goods by the gas stream is collected in the liquid trap on the intake side of the gas circulating pump and re-introduced via the liquid pump in atomized form on the compression side of the gas circulating pump.
Owing to the initially required, complete flushing of the vessel filled with the textile goods, the treatment liquor requirement corresponds approximately to the volume of the vessel less the volume occupied by the textile goods. The requirement is, therefore, considerable and is of the order of magnitude of what is required by the conventional technique with a long bath. A drawback of this method is the re-introduction of the excessive treatment liquor which in the subsequent bleaching process has to be supplemented by the component of bleaching liquor that was absorbed by the textile goods. Herein, soiling of the repeatedly used bleaching liquid as it flows through the textile goods is unavoidable. Moreover, conversion to other finishing methods without considerable loss of bleaching liquid or to other treatment baths and the products contained therein is not feasible.
Insofar this method does not offer any significant advantages over the wet finishing with the conventional long bath.
In the wet finishing method according to German published patent application 22 62 309, a system is used which again comprises a vessel closable in a pressure-tight manner with the textile goods arranged therein. The interior of the vessel communicates via a suction line with the intake side of a gas circulating pump. The compression side of this circulating pump is connected via a line to a heating device from which a further line leads to the vessel, more particularly, into the interior of the textile goods. Further lines discharge upstream and downstream of the heating device. These are connected to a dye vat from which the dye to be applied is injected into the connection line of the heating device and the interior of the textile goods.
In the performance of the method, the gas circulating pump is started, without any further preparatory work, and thereupon forces air through the textile goods. Simultaneously, the dye to be applied is atomized downstream of the heating device and conveyed to the textile goods by the circulating air.
This method does have the advantage of low dye consumption, but a feature, in particular, of this method is uneven dyeing of the textile goods, which is due to the fact that certain regions of the textile goods present in the form of spools receive less dye than others.
The application of dressing agent to webs of fabric by means of an aerosol is known from German patent 885 534. Webs of fabric, viewed in the flow direction of the aerosol, are very thin structures and so there is no danger of air occlusions to impede application of the dressing agent.